In January 1998, Axial Volcano experienced a submarine volcanic eruption. Research cruises to Axial every summer since then have been documenting changes at the site caused by the eruption. More information about this work can be found at the NeMO website, where daily updates are posted when scientists are at sea. Also check out NeMO Explorer, which has virtual reality views of the seafloor at Axial.
Axial Volcano rises 700 meters above the mean level of the ridge crest and is the most magmatically robust and seismically active site on the Juan de Fuca Ridge between the Blanco Fracture Zone and the Cobb offset. It represents the product of intense volcanic activity from the Cobb-Eikelberg hotspot juxtaposed on the extensional field of the spreading center. Axial Volcano was first studied in the late 1970s and then mapped in greater detail by NOAA/VENTS with SeaBeam in the early 1980s. Following the initial discovery of venting in the northern portion of the caldera in 1983, a concentrated mapping and sampling effort was made in the mid-late 1980s.The summit of Axial Volcano is marked by an unusual rectangular shaped caldera (3 x 8 km) that lies between the two rift zones. The caldera is defined on three sides by a boundary fault of up to 150 m relief. Hydrothermal vents colonized with biological communities are located near the caldera fault or along the rift zones. Two major high temperature vent areas include the ASHES vent field in the SW caldera and CASM in the north end. The caldera and the upper rift zones have been extensively surveyed by SeaMARC I sidescan sonar, towed camera systems, and submersible dives (see our Methods page for more informtion). The camera tows and submersible dives have revealed extensive areas of fresh lava and diffuse venting on the upper portions of the rift zones. T-phase monitoring of the Juan de Fuca Ridge since 1991 has shown that more than 90% of the on-axis events have originated from the summit of Axial Volcano, excluding the 1993 CoAxial intrusion. (What is a T-phase?). Seafloor instruments deployed in Axial caldera have recorded evidence for several possible intrusion events since 1988. All of these observations point to the fact that Axial is very active and dynamic, and is an excellent site to study the interaction between volcanic events and perturbations to its hydrothermal and biological systems.
The following 12 scientific papers were published in a special section about the 1998 eruption at Axial Volcano the journal Geophysical Research Letters.
Baker, E. T., C. G. Fox, and J. P. Cowen, In situ observations of the onset of hydrothermal discharge during the 1998 submarine eruption of Axial Volcano, Juan de Fuca Ridge, Geophys. Res. Lett., 26, 3445-3448, 1999.
Chadwick, W. W., Jr., R. W. Embley, H. B. Milburn, C. Meinig, and M. Stapp, Evidence for deformation associated with the 1998 eruption of Axial Volcano, Juan de Fuca Ridge, from acoustic extensometer measurements, Geophys. Res. Lett., 26, 3441-3444, 1999.
Cowen, J. P., R. Shackelford, D. McGee, P. Lam, E. T. Baker, and E. Olson, Microbial biomass in the hydrothermal plumes associated with the 1998 Axial Volcano eruption, Geophys. Res. Lett., 26, 3637-3640, 1999.
Dziak, R. P., and C. G. Fox, The January 1998 earthquake swarm at Axial Volcano, Juan de Fuca Ridge: Hydroacoustic evidence of seafloor volcanic activity, Geophys. Res. Lett., 26, 3429-3432, 1999.
Dziak, R. P., and C. G. Fox, Long-term seismicity and ground deformation at Axial volcano, Juan de Fuca Ridge, Geophys. Res. Lett., 26, 3641-3644, 1999.
Embley, R. W., W. W. Chadwick, Jr., D. Clague, and D. Stakes, The 1998 Eruption of Axial Volcano: Multibeam anomalies and seafloor observations, Geophys. Res. Lett., 26, 3425-2428, 1999.
Feely, R. A., E. T. Baker, G. Lebon, J. F. Gendron, J. A. Resing, and J. P. Cowen, Evidence for iron and sulfur enrichments in hydrothermal particles at Axial Volcano following the January-February 1998 eruption, Geophys. Res. Lett., 26, 3649-3652, 1999.
Fox, C. G., In situ ground deformation measurements from the summit of Axial Volcano during the 1998 volcanic episode, Geophys. Res. Lett., 26, 3437-3440, 1999.
Lupton, J. E., E. T. Baker, R. W. Embley, R. Greene, and L. Evans, Anomalous helium and heat signatures associated with the 1998 Axial Volcano event, Juan de Fuca Ridge, Geophys. Res. Lett., 26, 3449-3452, 1999.
McLaughlin-West, E. A., E. J. Olsen, M. D. Lilley, J. A. Resing, J. E. Lupton, E. T. Baker, and J. P. Cowen, Variations in hydrothermal methane and hydrogen following the 1998 eruption at Axial Volcano, Geophys. Res. Lett., 26, 3453-3456, 1999.
Resing, J. A., R. Feely, G. Massoth, and E. T. Baker, The water-column chemical signature after the 1998 eruption of Axial Volcano, Geophys. Res. Lett., 26, 3645-3648, 1999.
Sohn, R. A., S. C. Webb, and W. C. Crawford, Local seismicity following the 1998 eruption of Axial Volcano, Geophys. Res. Lett., 26, 3433-3436, 1999
Previous results from a broad range of studies at Axial Volcano were published in a special issue of the Journal of Geophysical Research (vol. 95, no. B8, August 10, 1990, p.12,689-12,966). The following are some selected scientific papers on the geology of Axial Volcano:
Appelgate, B., Volcanic and Structural Morphology of the Southern Flank of the Axial Volcano, Juan de Fuca Ridge: Results From a Sea MARC I Side Scan Sonar Survey, J. Geophys. Res., 95, 12,765-12,783, 1990.
Appelgate, B., and R. W. Embley, Submarine tumuli and inflated tube-fed lava flows on Axial Volcano, Juan de Fuca Ridge, Bull. Volcanol., 54, 447-458, 1992.
Chase, R.L., J.R. Delaney, J.L. Karsten, H.P. Johnson, S.K. Juniper, J.E. Lupton, S.D. Scott, V. Tunnicliffe, S.R. Hammond, and R.E. McDuff, Hydrothermal vents on an axis seamount of the Juan de Fuca ridge (Canadian American Seamount Expedition), Nature, 313, 212-214, 1985.
Embley, R. W., K. M. Murphy, and C. G. Fox, High resolution studies of the summit of Axial volcano, J. Geophys. Res., 95, 12785-12812, 1990.
Fox, C. G., Evidence of active ground deformation on the mid-ocean ridge: Axial Seamount, Juan de Fuca Ridge, April-June, 1988, J. Geophys. Res., 95, 12813-12822, 1990.
Fox, C. G., Five years of ground deformation monitoring on Axial Seamount using a bottom pressure recorder, Geophys. Res. Lett., 20, 1859-1862, 1993.
Hammond, S.R., Relationships between lava types, seafloor morphology, and the occurrence of hydrothermal venting in the ASHES vent field of Axial Volcano, Journal of Geophysical Research, 95, 12,875-12,893, 1990.
Jacobson, R.S., L.D. Bibee, R.W. Embley, and S.R. Hammond, A microseismicity survey of Axial Seamount, Juan de Fuca Ridge, Bulletin of the Seismological Society of America, 77(1), 160-172, 1987.
Johnson, H.P. and R.W. Embley, Axial Seamount: An active ridge axis volcano on the central Juan de Fuca Ridge, J. Geophys. Res., 95(B8), 12,689-12,696, 1990
last modified 11/09/01 by Bill Chadwick